Example syntax for Secure Copy (scp)

What is Secure Copy?

scp allows files to be copied to, from, or between different hosts. It uses ssh for data transfer and provides the same authentication and same level of security as ssh.

Examples

Copy the file "foobar.txt" from a remote host to the local host

$ scp your_username@remotehost.edu:foobar.txt /some/local/directory

Copy the file "foobar.txt" from the local host to a remote host

$ scp foobar.txt your_username@remotehost.edu:/some/remote/directory

Copy the directory "foo" from the local host to a remote host's directory "bar"

$ scp -r foo your_username@remotehost.edu:/some/remote/directory/bar

Copy the file "foobar.txt" from remote host "rh1.edu" to remote host "rh2.edu"

$ scp your_username@rh1.edu:/some/remote/directory/foobar.txt \ your_username@rh2.edu:/some/remote/directory/

Copying the files "foo.txt" and "bar.txt" from the local host to your home directory on the remote host

$ scp foo.txt bar.txt your_username@remotehost.edu:~

Copy the file "foobar.txt" from the local host to a remote host using port 2264

$ scp -P 2264 foobar.txt your_username@remotehost.edu:/some/remote/directory

Copy multiple files from the remote host to your current directory on the local host

$ scp your_username@remotehost.edu:/some/remote/directory/\{a,b,c\} .

$ scp your_username@remotehost.edu:~/\{foo.txt,bar.txt\} .

scp Performance

By default scp uses the Triple-DES cipher to encrypt the data being sent. Using the Blowfish cipher has been shown to increase speed. This can be done by using option -c blowfish in the command line.

$ scp -c blowfish some_file your_username@remotehost.edu:~

It is often suggested that the -C option for compression should also be used to increase speed. The effect of compression, however, will only significantly increase speed if your connection is very slow. Otherwise it may just be adding extra burden to the CPU. An example of using blowfish and compression:


    $ scp -c blowfish -C local_file your_username@remotehost.edu:~

SSH with private key authentication

How to Add ssh user on linux server ?


You can use the putyykey generator and generate the ssh key for the user and copy into the local computer.You can download the puttykey generator from the

URL: http://the.earth.li/~sgtatham/putty/latest/x86/puttygen.exe

The following are the steps for creating ssh user with the authentication :-

#adduser test

#passwd test

#cd /home/test

#mkdir .ssh

#cd .ssh

#vi authorized_keys
In which file paste the generated key and save
Then add this user into wheel group

#vi /etc/group
Wheel:root,test

# vi /etc/sudoers
search the below line and remove comment.
===============================
# Same thing without a password
%wheel ALL=(ALL) NOPASSWD: ALL
===============================


Tat's it.....

File path in PLESK

These are the some of the paths in PLESK server

1) Site Document root

/var/www/vhosts/domain.com

2) Apache config File

/var/www/vhosts/domain.com/conf

3) Apache include files directory

/etc/httpd/conf.d

4) DNS/Named path

/var/named/run-root/var

5) Statistics path

/var/www/vhosts/domain.com /statistics

6) Path for qmail

/var/qmail/mailnames

7) Php.ini Path

/etc/php.ini or /usr/local/psa/admin/conf/php.ini

8) Maillog path

/usr/local/psa/var/log/maillog

9) Error log Path

/home/httpd/vhosts/domain.com/statistics/logs/error_log

10) Domain Access logs

/home/httpd/vhosts/domainname.tld/statistics/logs/access_log

11) Domain backup path

/var/lib/psa/dumps/domains

12) Mysql Path

/var/lib/mysql/database_name

How to Enable Passwordless Authentication with SSH

        Often times you have automated scripts that require access to multiple machines from a single source and need to do so without having to deal with ssh password prompts. And in other instances you may have a bastian host (strong point) security model which you would like to have passwordless communication from. Below are 10 steps to setting up passwordless authentication with SSH in Linux.

Step 1:(*note server1 is the source server and server2 will be the destination server)

server1# mkdir ~/.ssh

Step 2:

server1# cd ~/.ssh

Step 3:

server1# ssh-keygen -t rsa

Generating public/private rsa key pair.
Enter file in which to save the key (“your_local_home”/.ssh/id_rsa):
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved in id_rsa.
Your public key has been saved in id_rsa.pub.
The key fingerprint is:
18:6a:e3:78:ab:2d:0c:8e:f9:67:f7:30:32:44:77:34 phil@server1

Step 4:

server1# scp ~/.ssh/id_rsa.pub phil@server2.philchen.com:/home/phil/id_rsa.server1.pub

Step 5:

server1# ssh phil@server2.philchen.com
Password:

Step 6:

server2# mkdir .ssh

Step 7:

server2# chmod 700 .ssh

Step 8:

server2# cat id_rsa.server1.pub >> .ssh/authorized_keys

Step 9:

server2# chmod 644 .ssh/authorized_keys

Step 10:

server2# exit
server1# ssh phil@server2.philchen.com

*Note repeat steps 4-10 for all target servers you would like passwordless access from server1

* FYI Ensure your /home/user directory has the permission 755 also!

You should be all set!

Difference between!!!!

1) SMTP and POP3:

SMTP Protocol:
The SMTP (Simple Mail Transfer Protocol) protocol is used by the Mail Transfer Agent (MTA) to deliver your eMail to the recipient's mail server. The SMTP protocol can only be used to send emails, not to receive them. Depending on your network / ISP settings, you may only be able to use the SMTP protocol under certain conditions.

The POP3 (Post Office Protocol 3) protocol provides a simple, standardized way for users to access mailboxes and download messages to their computers.When using the POP protocol all your eMail messages will be downloaded from the mail server to your local computer. You can choose to leave copies of your eMails on the server as well. The advantage is that once your messages are downloaded you can cut the internet connection and read your eMail at your leisure without incuring further communication costs. On the other hand you might have transferred a lot of message (including spam or viruses) in which you are not at all interested at this point.

2) IMAP vs.POP

The basic difference between IMAP and POP3 is that with POP3 you work most of the time offline because you only connect to the server to download new mail to your computer. This means you have to check your server mailbox periodically. Access from multiple computers/clients is possible by leaving your new mail on the server, but problematic. IMAP, on the other hand, allows you to always work with your mail live on the server. This means that a connection is made and typically maintained through your entire email session.

3) What is IMAP?

IMAP stands for Internet Message Access Protocol. It, like POP, is a way of accessing your email on servers. The primary advantage to IMAP is that since it maintains the original emails on the server, no matter how many different machines you login from you will have complete access to all your email. It also let’s you work with an unlimited number of server-side folders, which makes IMAP a perfect companion to server-side email filtering and Spam administration (see Procmail and Spamassassin).

Virtuozzo Command Line Utilities

The table below contains the full list of Virtuozzo command-line utilities.

General utilities are intended for performing day-to-day maintenance tasks:

vzctl	Utility to control Containers.
vzlist	Utility to view a list of Containers existing on the Node with additional information.
vzquota	Utility to control Virtuozzo Containers disk quotas.

Licensing utilities allow you to install a new license, view the license state, generate a license request for a new license:

vzlicview	Utility to display the Virtuozzo license status and parameters.
vzlicload	Utility to manage Virtuozzo licenses on the Hardware Node.
vzlicupdate	Utility to activate the Virtuozzo Containers installation, update the Virtuozzo licenses installed on the Hardware Node, or transfer the Virtuozzo license from the Source Node to the Destination Node.

Container migration tools allow to migrate Containers between Hardware Nodes or within one Hardware Node:

vzmigrate	Utility for migrating Containers from one Hardware Node to another.
vzmlocal	Utility for the local cloning or moving of the Containers.
vzp2v	Utility to migrate a physical server to a Container on the Node.
vzv2p	Utility to migrate a Container to a physical server.

Container backup utilities allow to back up and restore the Container private areas, configuration files, action scripts, and quota information:

vzbackup	Utility to back up Containers.
vzrestore	Utility to restore backed up Containers.
vzabackup	Utility to back up Hardware Nodes and their Containers. As distinct from vzbackup, this utility requires the Parallels Agent software for its functioning.
vzarestore	Utility to restore backed up Hardware Nodes and Containers. As distinct from vzrestore, this utility requires the Parallels Agent software for its functioning.

Template management tools allow the template creation, maintenance and installation of applications into a Container:

vzpkg	Utility to manage OS and application EZ templates either inside your Containers or on the Hardware Node itself.
vzmktmpl	Utility to create OS and application EZ templates.
vzveconvert	Utility to convert Containers based on Virtuozzo standard templates to EZ template-based Containers.
vzpkgproxy	Utility to create caching proxy servers for handling OS and application EZ templates.
vzrhnproxy	Utility to create RHN proxy servers for handling the packages included in the RHEL 4 and RHEL 5 OS EZ templates.
vzpkgls	Utility to get a list of templates available on the Hardware Node and in Containers.
vzpkginfo	Utility to get the information on any template installed on the Hardware Node.
vzpkgcreat	Create a new package set from binary RPM or DEB files.
vzpkgadd	Utility to add a new template to a Container.
vzpkglink	Utility to replace real files inside a Container with symlinks to these very files on the Node.
vzpkgrm	Utility to remove a template from a Container.
vzpkgcache	Update a set of preinstalled Container archives after new template installation.

Supplementary tools perform a number of miscellaneous tasks in the Hardware Node and Container context:

vzup2date	Utility to update your Virtuozzo software and templates.
vzup2date-mirror	Utility to create local mirrors of the Virtuozzo official repository.
vzfsutil	Utility for the VZFS optimization and consistency checking.
vzcache	Utility to gain extra disk space by caching the files identical in different Containers.
vzsveinstall	Utility to create the Service Container on the Hardware Node.
vzsveupgrade	Utility to update the packages inside the Service Container.
vzps and vztop	Utilities working as the standard ps and top utilities, with Container-related functionality added.
vzsetxinetd	Utility to switch some services between a standalone and xinetd-dependent modes.
vzdqcheck	Print file space current usage from quota's point of view.
vzdqdump and vzdqload	Utilities to dump the Container user/group quota limits and grace times from the kernel or the quota file or for loading them to a quota file.
vznetstat	Utility that prints network traffic usage statistic by Containers.
vzcpucheck	Utility for checking CPU utilization by Containers.
vzmemcheck	Utility for checking the Hardware Node and Container current memory parameters.
vzcalc	Utility to calculate resource usage by a Container.
vzcheckovr	Utility to check the current system overcommitment and safety of the total resource control settings.
vzstat	Utility to monitor the Hardware Node and Container resources consumption in real time.
vzpid	Utility that prints Container id the process belongs to.
vzsplit	Utility to generate Container configuration file sample, "splitting" the Hardware Node into equal parts.
vzcfgscale	Utility to scale the Container configuration.
vzcfgvalidate	Utility to validate Container configuration file correctness.
vzcfgconvert	Utility to convert Virtuozzo 2.0.2 Container configuration files to Virtuozzo 2.5.x format.
vzstatrep	Utility to analyze the logs collected by vzlmond and to generate statistics reports on the basis of these logs (in the text and graphical form).
vzreport	Utility to draw up a problem report and to automatically send it to the Parallels support team.
vzhwcalc	Utility to scan the main resources on any Linux server and create a file where this information will be specified.
vzveconvert	Utility to convert the Containers based on Virtuozzo standard OS templates to the EZ template-based ones.
vznetcfg	Utility to manage network devices on the Hardware Node.
vzmtemplate	Utility to migrate the installed OS and application templates from the one Hardware Node to another.

CentOS (RHEL) 4.4 FTP Install GUI Mode

How to install CentOS 4.4 (Red Hat Enterprise Linux) from an FTP server in GUI mode. This is knowledge which is needed for the RHCE Exam. The only prerequisite is that you have a server with and ftp server already running or the ability to install/start the/a ftp server.

1. If you are not currently running ftp on your server, you will need to setup the daemon. Here is the steps for a CentOS 4.4 server with no firewall configured and SELinux disabled:

   [root@localhost ~]# yum install vsftpd
    *** ouput removed as its of no interest ***
   [root@localhost ~]# chkconfig --level 35 vsftpd on
   [root@localhost ~]# /etc/init.d/vsftpd start
   Starting vsftpd for vsftpd:                                [  OK  ]

2. Create a directory on your ftp server in /var/ftp/pub (once again CentOS only). Mine is /var/ftp/pub/centos4.4.
   I will call this directory $CENTOS_FTP_ROOT.
   

   [root@localhost ~]# mkdir /var/ftp/pub/centos4.4
   [root@localhost ~]# cd /var/ftp/pub/centos4.4

3. Download the CentOS ISO files. You can download the DVD image or regular ISOs.
4. Extract all the ISOs or DVD into the $CENTOS_FTP_ROOT directory. You can do this by mounting the ISO directly and then copying the contents to $CENTOS_FTP_ROOT. This link is a good description on how to mount an iso.

   [root@localhost centos4.4]# pwd
   /var/ftp/pub/centos4.4
   [root@localhost centos4.4]# ls -al
   total 744
   drwxr-xr-x  8 root root   4096 Feb  5 22:32 .
   drwxr-xr-x  3 root root   4096 Feb  5 22:13 ..
   drwxr-xr-x  4 root root   4096 Feb  5 22:25 CentOS
   -rw-r--r--  1 root root   8859 Mar 18  2005 centosdocs-man.css
   -rw-r--r--  1 root root     78 Aug 23 15:29 .discinfo
   -rw-r--r--  1 root root  18009 Feb 28  2005 GPL
   drwxr-xr-x  2 root root  90112 Feb  5 22:25 headers
   drwxr-xr-x  3 root root   4096 Feb  5 22:25 images
   drwxr-xr-x  2 root root   4096 Feb  5 22:25 isolinux
   drwxr-xr-x  2 root root   4096 Feb  5 22:25 NOTES
   -rw-r--r--  1 root root   5781 Aug 23 14:37 RELEASE-NOTES-en
   -rw-r--r--  1 root root   7014 Aug 23 14:49 RELEASE-NOTES-en.html
   drwxr-xr-x  2 root root   4096 Feb  5 22:25 repodata
   -rw-r--r--  1 root root   1795 Feb 28  2005 RPM-GPG-KEY
   -rw-r--r--  1 root root   1795 Feb 28  2005 RPM-GPG-KEY-centos4
   -rw-r--r--  1 root root 569869 Aug 12 10:38 yumgroups.xml

5. Now that you have ftp server setup, test it:

   [root@localhost ~]# ftp localhost
   Connected to localhost.localdomain.
   220 (vsFTPd 2.0.1)
   530 Please login with USER and PASS.
   530 Please login with USER and PASS.
   KERBEROS_V4 rejected as an authentication type
   Name (localhost:root): anonymous
   331 Please specify the password.
   Password:
   230 Login successful.
   Remote system type is UNIX.
   Using binary mode to transfer files.
   ftp> cd /pub/centos4.4
   250 Directory successfully changed.
   ftp> dir
   227 Entering Passive Mode (127,0,0,1,172,204)
   150 Here comes the directory listing.
   drwxr-xr-x    4 0        0            4096 Feb 06 04:25 CentOS
   -rw-r--r--    1 0        0           18009 Mar 01  2005 GPL
   drwxr-xr-x    2 0        0            4096 Feb 06 04:25 NOTES
   -rw-r--r--    1 0        0            5781 Aug 23 19:37 RELEASE-NOTES-en
   -rw-r--r--    1 0        0            7014 Aug 23 19:49 RELEASE-NOTES-en.html
   -rw-r--r--    1 0        0            1795 Mar 01  2005 RPM-GPG-KEY
   -rw-r--r--    1 0        0            1795 Mar 01  2005 RPM-GPG-KEY-centos4
   -rw-r--r--    1 0        0            8859 Mar 18  2005 centosdocs-man.css
   drwxr-xr-x    2 0        0           90112 Feb 06 04:25 headers
   drwxr-xr-x    3 0        0            4096 Feb 06 04:25 images
   drwxr-xr-x    2 0        0            4096 Feb 06 04:25 isolinux
   drwxr-xr-x    2 0        0            4096 Feb 06 04:25 repodata
   -rw-r--r--    1 0        0          569869 Aug 12 15:38 yumgroups.xml
   226 Directory send OK.
   ftp>

6. Create an CD from the boot.iso in $CENTOS_FTP_ROOT/images/. Or download it here
7. Boot the CD.
8. Press enter at the prompt:
9. Select your language:
10. Select your keyboard type:
11. Choose FTP as your install method:
12. Configure your network, I use DHCP:
13. Put in the ip address or hostname of your ftp server on which you created $CENTOS_FTP_ROOT.
    Then put the path on the webserver to $CENTOS_FTP_ROOT. Mine is /var/ftp/pub/centos4.4.
14. Press Next:
15. Select which type of system you would like to install:
16. I am selecting auto partition:
17. Press Next:
18. Press Next:
19. Press Next:
20. Configure the network as you wish. I set my hostname:
21. Enable a firewall and SELinux or not, I did:
22. Select your language:
23. Choose your timezone:
24. Set your root password:
25. Change the package configuration if you wish:
26. Press Next:
27. Screenshot of the install:
28. Screenshot of post install configuration:
29. Press Reboot:
30. Congratulations! Your OS has started:

CentOS (RHEL) 4.4 NFS Install Text Mode

How to install CentOS 4.4 (Red Hat Enterprise Linux) from an NFS server in TEXT mode. This is knowledge which is needed for the RHCE Exam. The only prerequisite is that you have a server with nfs already running or the ability to start the nfs server.

1. If you are not currently running nfs on your server, you will need to setup the service. Here is the steps for a CentOS 4.4 server with no firewall configured and SELinux disabled:
   
[root@localhost ~]# chkconfig --level 35 nfs on
[root@localhost ~]# /etc/init.d/nfs start
Starting NFS services: [ OK ]
Starting NFS quotas: [ OK ]
Starting NFS daemon: [ OK ]
Starting NFS mountd: [ OK ]
2. Create a directory on your nfs server. Mine is /tools/centos4.4. I will call this directory $CENTOS_NFS_ROOT.
   
[root@localhost ~]# mkdir -p /tools/centos4.4
[root@localhost ~]# cd /tools/centos4.4
3. Export the $CENTOS_NFS_ROOT directory. The steps for CentOS 4.4:
   
[root@localhost centos4.4]# nano -w /etc/exports
[root@localhost centos4.4]# cat /etc/exports
/tools/centos4.4 *(ro,insecure,all_squash)
[root@localhost centos4.4]# exportfs -a
[root@localhost centos4.4]# showmount -e localhost
Export list for localhost:
/tools/centos4.4 *
4. Download the CentOS ISO files. You can download the DVD image or regular ISOs.
5. Extract all the ISOs or DVD into the $CENTOS_NFS_ROOT directory. You can do this by mounting the ISO directly and then copying the contents to $CENTOS_NFS_ROOT. This link is a good description on how to mount an iso.
   
[root@localhost centos4.4]# pwd
/tools/centos4.4
[root@localhost centos4.4]# ls -al
total 744
drwxr-xr-x 8 root root 4096 Feb 5 22:32 .
drwxr-xr-x 3 root root 4096 Feb 5 22:13 ..
drwxr-xr-x 4 root root 4096 Feb 5 22:25 CentOS
-rw-r--r-- 1 root root 8859 Mar 18 2005 centosdocs-man.css
-rw-r--r-- 1 root root 78 Aug 23 15:29 .discinfo
-rw-r--r-- 1 root root 18009 Feb 28 2005 GPL
drwxr-xr-x 2 root root 90112 Feb 5 22:25 headers
drwxr-xr-x 3 root root 4096 Feb 5 22:25 images
drwxr-xr-x 2 root root 4096 Feb 5 22:25 isolinux
drwxr-xr-x 2 root root 4096 Feb 5 22:25 NOTES
-rw-r--r-- 1 root root 5781 Aug 23 14:37 RELEASE-NOTES-en
-rw-r--r-- 1 root root 7014 Aug 23 14:49 RELEASE-NOTES-en.html
drwxr-xr-x 2 root root 4096 Feb 5 22:25 repodata
-rw-r--r-- 1 root root 1795 Feb 28 2005 RPM-GPG-KEY
-rw-r--r-- 1 root root 1795 Feb 28 2005 RPM-GPG-KEY-centos4
-rw-r--r-- 1 root root 569869 Aug 12 10:38 yumgroups.xml
6. Create an CD from the boot.iso in $CENTOS_NFS_ROOT/images/. Or download it here
7. Boot the CD.
8. Press enter at the prompt:
9. Select your language:
10. Select your keyboard type:
11. Choose NFS image as your install method:
12. Configure your network, I use DHCP:
13. Put in the ip address or hostname of your nfs server on which you created $CENTOS_NFS_ROOT. Then put the path on the webserver to $CENTOS_NFS_ROOT. Mine is /tools/centos4.4.
14. Select OK:
15. Select which type of system you would like to install:
16. I am selecting auto partition:
17. Crap, its going to delete all my data! Select Yes:
18. Select OK:
19. Select YES:
20. Select OK:
21. Select OK:
22. Select OK:
23. Select OK:
24. Select OK:
25. Select OK:
26. Configure the network as you wish:
27. Set your hostname:
28. Enable a firewall or not, I did:
29. Enable SELinux or not, I did:
30. Select your language:
31. Choose your timezone:
32. Set your root password:
33. Change the package configuration if you wish:
34. Select OK:
35. Screenshot of the install:
36. Screenshot of post install configuration:
37. Press Reboot:
38. Congratulations! Your OS has started: